Use of bacterium Pseudomonas proradixstrain DSMZ 13134 for the treatment of plants and/or seeds against an attack by a pathogen of the class peronosporomycetes, is claimed. Independent claims are also included for: (a) producing an agent, comprising providing the bacterium Pseudomonas proradixstrain DSMZ 13134 in a therapeutic amount to the plants, and formulating the bacterium; and (b) treating the plants and/or seeds, comprising providing plants and/or seeds and incubating them with a solution containing the bacterium Pseudomonas proradixstrain DSMZ 13134. ACTIVITY : Antimicrobial; Fungicide. The fungicidal activity of Proradix WG(RTM: Pseudomonas proradixstrain DSMZ 13134) (A) against Pythium ultimumwas tested in seeds of cucumber. The results showed that (A) (5 g) exhibited a fungicidal activity of 85%, where as the control group exhibited 66%. MECHANISM OF ACTION : None given.